Fetal Development

Fetal Development

Third Trimester

The fetus is about 10 inches long from crown to rump and weighs around 2 ½ pounds. [ View Picture ]

The eyes can perceive light, eyes can open and eyelashes are now present.

The woman may feel fetal respiratory movements as "hiccups".

Although immature, an otherwise normal fetus born at this time will often survive with expert care. In Alaska around 90% of fetuses born at 28 weeks gestation can survive with good care.

28 weeks after conception(30 weeks after the last menstrual period)

The fetus is 10 ½ inches long from crown to rump and weighs almost 3 pounds.

The lungs develop to the point where breathing air is possible, although help is usually needed. In Alaska, with good care, the survival rate is 96% or better for fetuses of 29 weeks gestation or more.

30 weeks after conception(32 weeks after the last menstrual period)

The fetus is about 11 inches long from crown to rump and generally weighs more than 3 pounds. [ View Picture ]

The skin is pink and no longer so transparent.

Toenails are now present.

From this stage on, fetal development is essentially complete, and growth is the primary change noted.

32 weeks after conception(34 weeks after the last menstrual period)

The fetus is about 12 inches long from crown to rump and generally weighs 4 to 4 ½ pounds.

Eyes close during sleep and open during alert times.

The skin becomes smoother and pink.

34 weeks after conception(36 weeks after the last menstrual period)

The fetus is 13 inches long from crown to rump and generally weighs about 5 to 5½ pounds. [ View Picture ]

Scalp hair is silky and lays against the head.

Muscle tone improves so the fetus can turn and lift its head.

36 weeks after conception(38 weeks after the last menstrual period)

The fetus is 13 ½ inches long from crown to rump and generally weighs between 5 ½ to 6 ½ pounds.

Lungs are usually mature.

The fetus can grasp firmly.

The fetus turns toward light sources.

The fetus is gaining about ½ ounce per day.

38 weeks after conception(40 weeks after the last menstrual period)

The fetus averages 14 ½ inches from crown to rump and an average of 20 inches in length from head to toe. [ View Picture ]